It is well known that polysiloxanes improve the spreading of oils on the surfaces of, for example, human skin, but also on the surfaces of plastics. Reference is made to the European publication 0 211 550 with regard to this state of the art. This relates to a composition, which contains the following:
(A) 5 to 95% by weight of an alkoxylated polyether having the formula ##STR1## wherein R represents a saturated or unsaturated C.sub.6-22 hydrocarbon group, which can be substituted by a hydroxyl group, and m represents 2 to 50, and PA1 (B) 95 to 5% by weight of tetra(dimethylcyclosiloxane) or penta(dimethylcyclosiloxane) or a mixture thereof. PA1 R.sup.2 in the polymer are the same or different and PA1 R.sup.3 represents the R.sup.1 or the R.sup.2 group, PA1 a has a value of 5 to 100, PA1 b has a value of 0 to 80, and PA1 c has a value of 0 to 5, PA1 (i) in the average molecule, at least two R.sup.2 groups are as defined in (1) and/or (2) above, PA1 (ii) a&gt;b and the sum of the units with the subscript a&gt;10, and PA1 (iii) the organopolysiloxane is homogeneously miscible with the oil in a concentration of 0.01 to 20% by weight, PA1 (1) linear or branched alkyl groups with 8 to 30 carbon atoms, wherein the alkyl groups can be interrupted by an oxygen atom, or PA1 (2) linear or branched alkoxy groups with 8 to 30 carbon atoms, wherein the alkyl group of the alkoxy groups can be interrupted by an oxygen atom. PA1 i) &gt;500 the sum of the units with the subscript a=12 to 35, the sum of the units with the subscript b=3 to 10, and the subscript c=0, PA1 ii) &gt;400 and &lt;500 the sum of the units with the subscript a =25 to 60, the sum of the units with the subscript b=5 to 15 and the subscript c=0, PA1 iii) &lt;400 the sum of the units with the subscript a=45 to 100, the sum of the units with the subscript b=3 to 20 and the subscript c=0. PA1 (i) &gt;50 mpas the sum of the units with the subscript a=12 to 60, the sum of the units with the subscript b=3 to 15, and the subscript c=0, PA1 (ii) &lt;50 mpas the sum of the units with the subscript a=26 to 100, the sum of the units with the subscript b=3 to 20, and the subscript c=0,
Polyethers, containing such silicone oils, can be used in the form of creams or lotions. They can also, however, be used as carriers for physiologically active substances, including pharmaceutical substances. The main property of such a preparation consists in its improved ability to spread on skin. The spreadability depends, among other things and in particular, on the surface tension of the preparation containing the silicone, reference being made in the European publication 0 211 550 to the paper by R. Keymer: "The Spreading of Liquid Lipoids on Skin", Pharm. Ind. 32 (7), 577-581 (1970).
Silicone waxes represent a further class of spreading agents, which have one or more long-chain alkyl groups linked to the silicone backbone. The melting point of the silicone waxes increases as the content of long-chain alkyl groups increases and as the chain length of the alkyl group increases. In this connection, reference is made to the paper "Silicone Surfactants", D. Schaefer, Tenside 1990, pages 154 to 158. These silicone waxes lower the surface tension of organic systems, such as the surface tension of mineral oils, and improve the spreading ability of cosmetic oils and waxes. As a rule, however, the spreading ability of mixtures of oils and silicone waxes is only slightly better than that of pure oils.
A disadvantage of the polysiloxanes, used as agents for improving the spreading ability, is their generally poor compatibility with oils, the compatibility (solubility) of the polysiloxanes with the oils decreases as the number of dimethylsiloxy units increases.
The invention is concerned with the technical problem of finding organopolysiloxanes, which have as good a compatibility with (solubility in) organic oils as possible and have the ability to improve the spreadability of the oils on surfaces, particularly on the human skin. The compounds are to be clearly effective in the least possible amounts and should be in a position to improve the spreading behavior even of oils of different structures.